Hello,
1/ In order to take a closer look at your settings, we kindly request that you provide us with temporary wp-admin access. If your site is live and you do not wish to share access, we suggest creating a staging site (full copy) and providing us with access. To provide wp-admin access, you can create a new user account with administrator role via the Dashboard, and provide us with the username and password via the Private Content area.
We thank you for your cooperation.
2/ It looks like the problem is cause by a 3rd party plugin on your site.
Try to disable “AJAX Add To Cart For Simple And Variable Products” via Theme Options and check how it works then.
Try to disable all the third-party plugins (including cache plugins), that does not come bundled with XStore https://xstore.helpscoutdocs.com/article/36-included-plugins, clear the cache of the browser, and check then. Maybe one of the additional plugins is the reason for the problem.
Kind Regards,
8theme team